Ou the structure of Taeiiiii coufusa Ward. 475 



such a dcscri])ti(»ii woie fouiul. 'J'he islhnms contaiiis iu addition to 

 tlic lüii-^ittulinal tibrcs, sonic piirciicliyina aiid usually a fcw traiisverso 

 and sagiltal tibrcs. This poiut was vcrirtcd in sagittal, frontal and 

 transvcrse sections of proglottids in diffcrent stages of devel()i)ment. 

 Somc of the fibrcs ncar thc surfacc it is truc attach to thc ordinary 

 spiudlc cells lying uext to thc cuticula, Nvhcre it dips down slightly 

 between the proglottids, but the maiu niass extends on through into 

 the next segment. 



The connection between the various proglottids seems to be the 

 niost firm at thc sides near the inner cdges of thc lougitudinal ex- 

 cretory canal, thesc points offen being tied together by the longi- 

 tiulinal muscles fibrcs whcn all thc remaining tissues are free. The 

 l)roglottids do not in all cases separate along the line marked out on 

 the exterior of the worm, but not infrequently break at the cross 

 excretory canal, which in this form lies very near the posterior cdge 

 of the proglottids (Fig. 5 t.t.c). This fact was noticed many times iu 

 pulling the proglottids apart. 



The transverse muscles do not show so much of a teudency to 

 run iu bundlcs as the lougitudinal, and are in general smallcr. They 

 form two plates (Fig. 4 i.m) between which the sexual organs are 

 locatcd. Under the low power they have the appearance of a con- 

 tinuous band but under the higher power they are found to spread at 

 thc ends near the edges of thc proglottid and for the most part at- 

 tached to its walls. In the neighborhood of the pore especially their 

 spreading and attachments become very piain. The large central 

 plug in thc pore is well supplied with them. Occasionally they niay 

 be Seen entirely outside the plate and lying in the cortical layer. 



The sagittal fibrcs (Fig. 4 and 5 sjn) cross the proglottids from 

 dorsal to ventral surfaces and are scarcely visible under the low 

 power. Those lyiug in the middle portion of the proglottid have thc 

 appearance of conuecting the two transvcrse muscles plates but the 

 higher powers of the microscope show that in reality they pass on, 

 for the most part into the cortical layer. It is due largely to the 

 direction of these fibrcs that the ends of the transverse plates seem 

 to unite or bend around into onc another. These fibrcs are the 

 smallest of the three kinds mcntioned and show little tendency to run 

 in bundlcs. Offen they may be traced across the middle field, through 

 thc transverse bands and on into the cortical layer, where in somc 

 cases, they attach to the spindle - shapcd cells w'hich abut on the 

 cuticula. Xear the center of thc proglottid they seem to be somc- 



